Doesn't work if you have SSL enabled for the site in question as this will also modify the SSL VirtualHost port from 443 to 8000. I really think we should have a setting for this in ispconfig3 interface. If there already is one I would be very happy if someone could point me to where it is.

EDIT: This works if you have SSL for the site, just in case someone else is looking for a solution. Not really sure abt the tmpl syntax so it might be a bit redundant, but it works :